The invention generally relates to a well completion system and more particularly relates to a sandface completion.
Several downhole trips, or runs, typically are required to complete a well. For example, several trips typically are required to perforate and gravel pack the well.
As an example, the following procedure may be used to perforate and gravel pack a well. First, a string with a plug running tool is run downhole to install a plug in a previously-installed sump packer. The string is withdrawn from the well, and in a subsequent trip, a string that contains one or more perforating guns is lowered into the well. The perforating charges of the gun(s) are then fired; and subsequently, this string is pulled out of the well. Next, a cleanup string that contains, for example, a circulation valve, scraper and washing tool may be run downhole for purposes of cleaning the well. The cleanup string is pulled out of the well, and subsequently, another string is run downhole to remove the plug from the sump packer. After the string that removes the plug is retrieved from the well, a string that contains a bottom hole assembly is run into the well. The bottom hole assembly typically includes a sandscreen to support a filtering gravel substrate that is deposited around the sandscreen in a subsequent gravel packing operation. The running string (the portion of the string above the bottom hole assembly) is retrieved from the well upon completion of the gravel packing operation.
In general, the fluid loss in the well increases with the number of downhole trips. Fluid losses invade the formation, and may have such detrimental effects as increasing the skin, causing near wellbore damage and impairing the overall productivity of the well.
Thus, there is a continuing need for better ways to reduce the number of trips into a well for purposes of performing completion operations, such as perforating and gravel packing operations.